While visiting with a neighbor today, she handed me a string of white LED lights that had suffered squirel damage. The end female outlet had been removed and only 50% of the LED's lit.
Closer examination revealed two tiny 3A fuses inside the plug, and one lump in-line which I took for a current limiting resistor.
I pulled the fuses & checked them with my DVM. No joy. Upon replacement, the same half was still dark. I unplugged the strand and made some continuity measurements and marked off the three strands to keep them separate.
For brevity, lets say there are two circuits, each with 20 LEDS. One's lit, one's dark. I pulled one of the 'dark' ones and meas. a resistance of ~ 85Ohms. Pretty high. Swapped the leads and checked again; same. Switched the Fluke to 'diode' meas. It beeped, indicating continuity, but very low fwd V. Swapped the leads: same.
I pulled one from the lit ckt, meas. resistance and it was infinite. Swapped leads: same. Switched to diode mode: open (infinite). Swapped leads: same.
So obviously these are not 'regular' LED's and the Fluke didn't supply enough V, nor I to turn them on.
I pulled out an inductive toner I use to find which breaker goes with which outlet, and while it works well on incandescent mini-lights, no joy with LED's.
After testing ALL the 'dark' LEDS on the 'dark' ckt, I found they all were defective (shorted) but still allowed current to pass though they remained unlit.
Evidently when Mr. Squirel chewed through the insulation, a short occured on that ckt, all the LED's were Tango Uniform and a fuse blew.
So if you get a strand of these that only one ckt works and you have a DVM, the likely bad ones will read anything other than infinite.
Anyone else tested some of these? How did you diagnose? I still haven't switched completely over, but also don't spend time wrapping trees, spanning large distances overhead with lights, etc. like some of the neighbors. Definitely looks festive, but they've spent > $600 on LED strings. I save my few for the tree where no squirels can get at them.
Closer examination revealed two tiny 3A fuses inside the plug, and one lump in-line which I took for a current limiting resistor.
I pulled the fuses & checked them with my DVM. No joy. Upon replacement, the same half was still dark. I unplugged the strand and made some continuity measurements and marked off the three strands to keep them separate.
For brevity, lets say there are two circuits, each with 20 LEDS. One's lit, one's dark. I pulled one of the 'dark' ones and meas. a resistance of ~ 85Ohms. Pretty high. Swapped the leads and checked again; same. Switched the Fluke to 'diode' meas. It beeped, indicating continuity, but very low fwd V. Swapped the leads: same.
I pulled one from the lit ckt, meas. resistance and it was infinite. Swapped leads: same. Switched to diode mode: open (infinite). Swapped leads: same.
So obviously these are not 'regular' LED's and the Fluke didn't supply enough V, nor I to turn them on.
I pulled out an inductive toner I use to find which breaker goes with which outlet, and while it works well on incandescent mini-lights, no joy with LED's.
After testing ALL the 'dark' LEDS on the 'dark' ckt, I found they all were defective (shorted) but still allowed current to pass though they remained unlit.
Evidently when Mr. Squirel chewed through the insulation, a short occured on that ckt, all the LED's were Tango Uniform and a fuse blew.
So if you get a strand of these that only one ckt works and you have a DVM, the likely bad ones will read anything other than infinite.
Anyone else tested some of these? How did you diagnose? I still haven't switched completely over, but also don't spend time wrapping trees, spanning large distances overhead with lights, etc. like some of the neighbors. Definitely looks festive, but they've spent > $600 on LED strings. I save my few for the tree where no squirels can get at them.
